code: def test_basesearchcv_parse_options():
      """Check that _parse_options explodes nested dictionaries."""
      param_grid = {
          "bsl_options": {"method": ["als", "sgd"], "reg": [1, 2]},
          "k": [2, 3],
          "sim_options": {
              "name": ["msd", "cosine"],
              "min_support": [1, 5],
              "user_based": [False],
          },
      }
      gs = GridSearchCV(SVD, param_grid)
      parsed_params = gs.param_grid
      assert len(parsed_params["sim_options"]) == 4  # 2 method x 2 reg
      assert len(parsed_params["bsl_options"]) == 4
  
file_path: Surprise/tests/test_search.py
imports: import os
  import numpy
  import pytest
  from scipy.stats import randint, uniform
  from surprise import Dataset, Reader, SVD
  from surprise.model_selection import cross_validate, GridSearchCV, KFold, PredefinedKFold, RandomizedSearchCV
label_desc: Use image node_id 1 for calling a global function with example usage: test_basesearchcv_parse_options() without return types